Java 发送邮件

依赖：

        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>mail</artifactId>
            <version>1.4.7</version>
        </dependency>

代码：

package cn.edu.buaa.act.mail;

import java.util.Date;
import java.util.Properties;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.mail.Address;
import javax.mail.Authenticator;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

public class SendEmail {

    private boolean validate = true;
    // 发送者邮箱名
    private String username = "monitor_car";
    // 发件人邮箱
    private String FROM = username + "@163.com";
    // 发送者邮箱密码
    private String password = "xxxx123";
    // 邮件显示的发件人
    private String FROM_NAME = "zhangyang";
    // 邮件服务器
    private String Email_Host = "smtp.163.com";
    // 邮件标题
    private String Email_Subject = "开会通知";
    // 邮件头
    private String Email_Header = "This Is Email Header";
    // 邮件内容
    private String Email_Body = "<a href="http://www.baidu.com">This Is Email Body</a>";
    // 收件人邮箱
    private String TO = "xxxx@163.com";

    public void doSendEmail(int mailType) {

        // 获取系统环境
        Properties prop = new Properties();
        Authenticator auth = null;
        // 判断发送邮件是否需要验证
        if (validate) {
            // 邮件服务器认证 用户名和密码
            auth = new Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication(username, password);
                }
            };
        }
        // 添加必要的信息
        prop.put("mail.smtp.host", Email_Host);
        prop.put("mail.smtp.auth", validate);

        // 设置对话和邮件服务器进行通讯
        Session session = Session.getDefaultInstance(prop, auth);
        // 在控制台显示Debug信息
        session.setDebug(true);
        // 设置邮件对象
        Message message = new MimeMessage(session);
        try {
            // 设置邮件主题
            message.setSubject(Email_Subject);
            // 设置邮件标题
            message.setHeader("Header", Email_Header);
            // 设置发送时间
            message.setSentDate(new Date());

            // 设置发信人地址 和 名字
            Address address = new InternetAddress(FROM, FROM_NAME);
            // 把发件人信息添加到信息中
            message.setFrom(address);

            // 设置发件人地址
            Address toAddress = new InternetAddress(TO);
            // 设置接收人地址
            message.setRecipient(Message.RecipientType.TO, toAddress);

            // 设置多个收件人地址
            // message.addRecipient(Message.RecipientType.TO,new
            // InternetAddress("xxx@xxx.com"));

            // 设置邮件格式
            switch (mailType) {
            case 1:// 发送纯文本邮件
                message.setContent(Email_Body, "text/plain; charset=utf-8");
                break;
            case 2:// 发送html邮件
                message.setContent(Email_Body, "text/html; charset=utf-8");
                break;
            case 3:// 发送附件
                message.setContent(Email_Body, "text/html; charset=utf-8");

                Multipart multipart = new MimeMultipart();
                // 邮件正文部分
                BodyPart messageBodyPart = new MimeBodyPart();
                messageBodyPart.setText("bodypart");
                multipart.addBodyPart(messageBodyPart);

                // 邮件附件部分
                messageBodyPart = new MimeBodyPart();
                // 设置上传的资源
                DataSource source = new FileDataSource("C:/Users/zsm/Desktop/省级行政图.jpg");
                // 添加到
                messageBodyPart.setDataHandler(new DataHandler(source));
                // 设置文件名称,记得后缀名
                messageBodyPart.setFileName("tmp.jpg");
                multipart.addBodyPart(messageBodyPart);

                message.setContent(multipart);
                break;
            default: {
                System.out.println("要发送的邮件类型错误");
                System.exit(1);
            }
            }

            // 保存上面添加的信息
            message.saveChanges();
            // 发送邮件
            System.out.println("类型 " + mailType + "开始发送邮件……");
            Transport.send(message);
            System.out.println("发送成功！");
        } catch (Exception e) {
            System.out.println("出错");
            e.printStackTrace();
        }
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        new SendEmail().doSendEmail(1);
    }
}